Sampling apparatus



June 10, 1958 c. D. KEITH 2,837,920

MPLING APPARATUS ggg 54 TFT 9:2.

INVENTOR g 57 CARL D- KEITH RNEY C. D. KEITH SAMPLING APPARATUS June 10, 1958 2 Sheets-Sheet 2 Filed March 29, 1955 INVENTOR CA RL D. KEITH nited States Patent fiice 2,837,920 Patented June 10, 1958 2,837,920 SAMPLING APPARATUS Carl D. Keith, Munster, Ind., assignor to Sinclair Research Laboratories, Inc., Harvey, IlL, a corporation of Maine Application March 29, 1955, Serial No. 497,694 1 Claim. (Cl. 73-424) The present invention relates to the art of sampling heterogenous mixtures as for example mixtures of solid particles and slurries. More particularly, this invention relates to an apparatus for dividing a sample of solid particles into a plurality of portions each of which has a particle size distribution and composition representative of the original sample.

Adequate control of many chemical processes employing or producing particle materials requires frequent tests of materials at various stages in the process. As it is impractical to test the entire quantities involved, an art of sampling portions. of the mass, gathered in a manner tending to insure representation of the total, has developed. The gathered material is then divided into smaller portions and such testsas necessary are conducted on these ultimate portions. sary that the division effected on the sample result in portions representative of the sample as the sample should be representative of the original stream. For error in splitting the sample can magnify errors in the original sampling and completely destroy its significance.

I have now devised an apparatus capable of dividing a sample into a plurality of portions representative of the sample. My apparatus can divide samples accurately without regard to the composition, amount, number of portions resulting and do so in a manner substantially independent of operator technique. While thefapparatus can effectively split samples without regard to the use contemplated, it is especially advantageous. for division'of a sample for particle size determination.

Thus,my invention comprises a rotatable cylindrical member. having a bore through its center, the upper portion of the bore being funnel shaped, means spaced below the bore and associated with said cylindrical memher and adapted to disperse the particles circumferentially of the bore, and a receiving means disposed about the dispersion means and divided into. a plurality of chambers to receive the dispersed particles.

My invention will be readily understood by reference to the attached drawings in which:

Figure 1 is a side elevational view of an operative embodiment of my invention, 'and- Figure 2 is a transverse sectional view taken along lines 22 of Figure 3, and

Figure 3 is a longitudinal partial sectional view taken along lines 33 of Figure 1, andv Figure 4 is a transverse sectional view taken along lines 4-4 ofFigure 3.

Referring to Figure l, the

apparatus of this invention includes rotatable member 10 through which. particle sample to be divided is introduced. A cylindrical ,re-

ceiving chamber 12 is supportingly disposed beneath the rotatable member 19. The longitudinal axes of members l and 12 are in vertical alignment. Receiving chamber 12 is provided with channel openings 14 in its lower end portion to facilitate discharge of the portions collected into suitable receptacles, such as beakers 16. The receiving chamber 12 is supportingly mounted on a suitable shaft 18 which in turnmay be fixedto a base member 20 by a means 22 such as a lock nut or similar means.

It is, of course, just as neces- Rotational movement for rotatable, member 10 is provided-by a means 24, advantageously an electric motor, provided with a drive wheel 26 which is connected to the rotatable member by a suitable drive belt 28. The entire driving mechanism can be supportingly mounted on the receiving chamber 12 of the divider by means of a conventional bracket 30.

Referring now to Figure 3, rotatable member 10 has a bore 32 through its longitudinal axis. The upper portion 34 of bore 32- is enlarged into a funnel-shaped opening to facilitate charging of the apparatus and to permit maintenance of a headof particles on the particles passing downwardly through the bore 32 during operation of the apparatus. Spaced below the lower end of the bore 32 is dispersion means 36; advantageously, dispersion means 36 takes the form of a flat circular plate. The dispersion means 36 is spaced from and affixed to rotatable member 10 by means 38, i. e. threaded bolts. Thus, during. operation, rotation of member 10 effects simultaneous and equal rotation. of the dispersion means. Thev diameter of the dispersion means 36 is such that during. operation, all particles exiting the lower end of the bore 32'. strike the dispersion means; in general a dispersion means having a diameter as large as, and preferably slightly larger than, the internal diameter of the lower end of the bore 32 is employed.

Rotatablemember 10; is supportingly mounted on the upper portion of cylindricali receiving chamber 12 in a manner permitting rotation: of member 10 without rotating chamber 12. Advantageously, this is accomplished by cutting away the lower portion of member 10 to result in a flange-like annular extension 42. An annular groove is then cut into the flanged area. The internal rim 44 of the upperend portion of the receiving chamber 12 is also provided with an annular groove and a bearing race- 46 placed between these mated grooves facilitates the support of member 10 in a manner permitting its rotation.

Cylindrical receiving chamber 12 extends upwardly toa. point at least level with the lower end of the bore 32 of member 10. Thus, an annular space 48 is defined about the circumference of the dispersion means 36. Immediately below the dispersion means 36 is a nest or partitioning means 50 (refer especially to Figure 2) dividing the receiving chamber 12 into a plurality of vertically elongated portions such as. 51, 53, 55 and 57 (refer to Figure 2). The partitioning arrangement chosen, of course, is determined by the division of the sample desired. For example. a part of the sample can be divided. out by employing a partitioning means which includes at least one section defining a cross-sectional area of the total. Any. other division desired also can be elfected merely by providing a suitable partitioning means. In the embodiment shown, the receiving chamber 12 is divided into four portions.

The lower end portionof receiving chamber 12 ad vantageously is adapted; to direct the particles collected in each portion to bins or receptacles 16such as the beakers shown in the drawings. This can. be accomplished in various ways. One particularly eflicacious manner involves providing; receiving chamber 12 with a lower end. member 54 having a plurality ofchannels 14, one for each portion of the receiving chamber, terminating about the lower circumference of member 54. Beakers 16, placed under the end of the channels, would then receive all materials passing through the channels. Advantageously, the ends of channels 14 opening internally of the receiving chamber 12 are adapted to permit all ofthe material in the respective portions of the receiving chamber 12 to enter. In the embodiment shown, this is accomplished by reaming orcountersinking theupper opening of the channels as at 60 in Figure 3 so that 3 each opening extends over substantially the entire crosssectional area of the portion served. End member 54 may be provided with grooves 61 to receive the partitioning means (see Figure 4).

For best results in using my invention, the splitter apparatus should be as level as is conveniently possible to make it. To this end, I have provided in base member a leveling means 62 and screw legs 64. Advantageously, the leveling means 62 can take the form of a bubble gauge. The legs then are adjusted until the hubble indicates a level apparatus.

In operation, the apparatus is leveled and beakers are placed under the exit channels 14. The motor is started and adjusted to result in a speed of the rotatable member 10 of about 110 R. P. M. Different speeds of rotation can be employed as desired. In general, slower speeds decrease accuracy of the division efiected and while increased speeds normally result in increased efficiency of division, particles breakage will tend to increase and in the instance of catalyst size determinations is generally undesirable. A sample to be split is poured into the funnel shaped entrance 34 of bore 10 at a rate sufliciently rapid to fill the bore and part of the funnel. A head of particles is maintained in the funnel because intermittent free fall would tend to decrease accuracy. The particles pass downwardly through bore 32 and into contact with the dispersion means 36 whereupon they are thrown outwardly, or circumferentially of the bore, and thus fall into the various chambers or portions of the receiving chamber. Particles collected in each portion of the receiving chamber are delivered to the separate beakers for such use as desired.

The apparatus of this invention permits the use of a continuous sampling procedure, a singular convenience in handling small samples. The principle of continuous sampling has been objected to on the basis that a stream of solid particles is usually not uniform. The present apparatus overcomes this objection by rotating the stream being split at a rate sufficiently rapid that the stream can be considered'as homogeneous. Rotation of the rotatable member etfects the stream homogenization which contributes to the advantages obtained by use of the instant invention. While rotation of other elements of the apparatus does not afiect the relative distribution of particles in the stream entering the splitter, rotation of other elements is advantageous in achieving even greater accuracy. Thus, the partitioning means, the receiving chamber, and the particle receiving means, e. g., when in the form of a circular pan having thin wall divisions, may each or all be-rotated along with rotatable member 10; and they may be rotated at the same or difierent speeds and in the same direction as member 10 or in the opposite direction and in any event will result in insuring spread of any error in the system.

The following specific example demonstrates the results which can be obtained with the apparatus of the present invention.

EXAMPLE I Two hundred grams of a-catalyst composite were used in this experiment; the composite had the following screen analysis:

The test catalyst was passed through the sample splitter which was rotated at a rate of 110 R. P. M.s, and each of the resulting four portions were screen analyzed by running for 15 minutes on the Ro-Tap. The results are as follows:

Table I1 [Portion 1=50.67 gs.]

Deviation Wt. perfrom cal- Mesh Grams een culatcd analysis,

percent The following is a calculated screen analysis for a composite of the four portions:

Table III Mesh Grams Wt. per- 7 cent The increase in weight shown in the screen analysis as compared with the sum of the portions obtained from the splitter resulted from water adsorption as the catalyst employed was hygroscopic and the screen analysis was made with the catalyst subjected to the atmosphere; the sample division was efiected in a dry box in a dry air atmosphere. The excellent division of the ongrnal sample into portions having a particle size distribution representative of the sample is readily apparent from the above data. These results were. achieved notwithstanding the fact that the apparatus was not as level as can be expected when the splitter is on a level laboratory bench and that the sample was passed through the splitter five times, prior to the division noted, to obtain information 75 on breakage which may be expected in operation. Breakage was found to be negligible compared to breakage occurring in screen analysis with the Ro-Tap.

What is claimed is:

Apparatus of the type described which consistsessentially of a cylindrical member, a partitioning means disposed Within said member dividing the member into a plurality of vertically elongated portions, outlet means in the bottom of each of the plurality of portions of said cylindrical member, a rotatable member disposed above said cylindrical member having an unobstructed bore through its longitudinal axis, the upper portion of said bore flaring outwardly defining a funnel shaped entrance for said bore, said rotatable member having its vertical axis in alignment with the vertical axis of said cylindrical member, said rotatable member being mounted on said cylindrical member by a means permitting rotation of said rotatable member, and a fiat dispersion plate disposed below the bore of said rotatable mem- References Cited in the file of this patent UNITED STATES PATENTS 518,915 Clarkson Apr. 24, 1894 573,610 Moore Dec. 22, 1896 580,293 Calkins Apr. 16, 1907 

